Molarity & dilution worksheet with answers

Free printable Molarity & dilution worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
250 mLc = 0.15 mol/L

What mass m of NaCl (M = 58.44 g/mol) do you need to make 250 mL of a 0.15 mol/L solution?

V = 250 mLc = 0.15 mol/LM = 58.44 g/mol
m = g
2.Easy
24 g Na2​CO3​V = 1000 mL

24 g of Na2CO3 (M = 105.99 g/mol) is dissolved in water to make 1000 mL of solution. Find the molarity c.

m = 24 gM = 105.99 g/molV = 1000 mL
c = mol/L
3.Medium
2 mol/LV1​ = ?0.25 mol/L100 mL

You need 100 mL of 0.25 mol/L solution and have a 2 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 2 mol/Lc2 = 0.25 mol/LV2 = 100 mL
V1 = mL
4.Medium
2 mol/LV1​ = ?0.4 mol/L200 mL

You need 200 mL of 0.4 mol/L solution and have a 2 mol/L stock solution. What volume V1 of stock solution do you need?

c1 = 2 mol/Lc2 = 0.4 mol/LV2 = 200 mL
V1 = mL
5.Hard
1.5 mol/L200 mL2.5 mol/L100 mLc = ?300 mL

200 mL of a 1.5 mol/L solution is mixed with 100 mL of a 2.5 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 1.5 mol/LV1 = 200 mLc2 = 2.5 mol/LV2 = 100 mL
c = mol/L
6.Hard
0.1 mol/L150 mL2.5 mol/L50 mLc = ?200 mL

150 mL of a 0.1 mol/L solution is mixed with 50 mL of a 2.5 mol/L solution of the same substance. Find the concentration c of the mixture (volumes are additive).

c1 = 0.1 mol/LV1 = 150 mLc2 = 2.5 mol/LV2 = 50 mL
c = mol/L

Answer key

  1. 1. m = 2.192 g
  2. 2. c = 0.2264 mol/L
  3. 3. V1 = 12.5 mL
  4. 4. V1 = 40 mL
  5. 5. c = 1.833 mol/L
  6. 6. c = 0.7 mol/L

Full step-by-step solutions: practise this topic on examproblems.com.